LTE Inches Closer to Roaming the GlobeLTE Inches Closer to Roaming the Globe

4G LTE roaming has always had two challenges: one technical -- hopping disparate spectrum bands and networks -- and one commercial -- getting the operators to work together and hash out network-sharing deals.

At the LTE World Summit in Amsterdam this week, there's been some important progress made on the latter.

Leading up to the show, Swisscom announced it would support LTE roaming powered by Ericsson's new Diameter Signaling Controller. It's claiming to be the first European operator to take roaming across the globe, starting in South Korea, Canada and Hong Kong. (See Euronews: Swisscom Boasts LTE Roaming.)

Telenor International will also begin offering LTE roaming using Tekelec's diameter routing gear. The pair says that by working together they'll enable national and international roaming along with over-the-top services like VoIP. (See Telenor Global Uses Tekelec's DSR.)

These may seem like fairly limited implementations – Swisscom will only roam to South Korea at first, for example. But the fact that LTE roaming is picking up momentum is important as the number of LTE networks and the amount of data they carry continue to multiply.

According to a Telecoms.com report from the LTE Summit, Tommy Ljunggren, VP of system development at TeliaSonera, said that rolling out just one roaming agreement can take four to six months. Considering that the Global Mobile Suppliers Association says there are 156 commercial LTE networks deployed as of March, linking them all up is no small task. The operators, however, are eager to do so given the revenues they are losing when traveling customers disconnect.

That's why interconnect vendors like Tekelec and iBasis that serve as the central point to connect a number of different operators are picking up steam. (See LTE Roaming Action Intensifies.)

This week, iBasis has announced deals with both TeliaSonera International and Chunghwa Telecom. TeliaSonera is hooking up its Diameter signaling and data hubs with the vendor's to enable interoperability across its footprint of partners. And, in Taiwan, Chunghwa is tapping iBasis to offer LTE roaming, along with a number of services over its IPX, including HD voice, GRX, SMS, LTE signaling and voice-over LTE. (See TeliaSonera Int. & iBasis Team on LTE Roaming and iBasis, Chunghwa Strike IPX Accord.)

As the operators continue to rack up roaming agreements and their handset makers continue to work out the technical issues related to LTE roaming -- like supporting enough bands in the handset while keeping costs down -- they will soon be able to tackle LTE roaming's next biggest challenge: monetization. (See Talkin' the Low Down LTE Roaming Blues.)

"We expect the monetization of LTE roaming to happen now but continue at a faster pace after a critical level of the LTE subscribers start using LTE, and the necessary roaming interconnects are achieved over the next few months," iBasis CTO Ajay Joseph writes in an email to Light Reading.

— Sarah Reedy, Senior Editor, Light Reading